Dose-volume thresholds and smoking status for the risk of treatment-related pneumonitis in inoperable non-small cell lung cancer treated with definitive radiotherapy.
OBJECTIVE
To identify clinical risk factors and dose-volume thresholds for treatment-related pneumonitis (TRP) in patients with non-small cell lung cancer (NSCLC).


METHODS
Data were retrospectively collected from patients with inoperable NSCLC treated with radiotherapy with or without chemotherapy. TRP was graded according to Common Terminology Criteria for Adverse Events, version 3.0, with time to grade > or = 3 TRP calculated from start of radiotherapy. Clinical factors and dose-volume parameters were analyzed for their association with risk of TRP.


RESULTS
Data from 576 patients (75% with stage III NSCLC) were included in this study. The Kaplan-Meier estimate of the incidence of grade > or = 3 TRP at 12 months was 22%. An analysis of dose-volume parameters identified a threshold dose-volume histogram (DVH) curve defined by V(20) < or = 25%, V(25) < or = 20%, V(35) < or = 15%, and V(50) < or = 10%. Patients with lung DVHs satisfying these constraints had only 2% incidence of grade > or = 3 TRP. Smoking status was the only clinical factor that affected the risk of TRP independent of dosimetric factors.


CONCLUSIONS
The risk of TRP varied significantly, depending on radiation dose-volume parameters and patient smoking status. Further studies are needed to identify biological basis of smoking effect and methods to reduce the incidence of TRP.
Jin
Hekun
H
Department of Radiation Oncology, Hunan Tumor Hospital and Institution, Hunan, China.
Tucker
Susan L
SL
Liu
Hui Helen
HH
Wei
Xiong
X
Yom
Sue Sun
SS
Wang
Shulian
S
Komaki
Ritsuko
R
Chen
Yuhchyau
Y
Martel
Mary K
MK
Mohan
Radhe
R
Cox
James D
JD
Liao
Zhongxing
Z
D000970:Antineoplastic Agents / Q000627:therapeutic use; D002289:Carcinoma, Non-Small-Cell Lung / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D015897:Comorbidity; D004307:Dose-Response Relationship, Radiation; D005260:Female; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D017564:Radiation Pneumonitis / Q000453:epidemiology / Q000209:etiology*; D011879:Radiotherapy Dosage; D012189:Retrospective Studies; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects*; D016896:Treatment Outcome
D000970:Antineoplastic Agents